#!/usr/bin/env node

const (Readable)=require('stream');

let c ='a'.charCodeAt(0);
class MyReadable extends Readable{
  constructor(){
    super();
  }
  _read(){

    this.push(String.formCharCode(this.#c++));
    if(this.#c>'z'.charCodeAt(0)){this.push(null)
  }



}}
let rs=new MyReadable();
re.pipe(process.stdout);
